Simulating X-ray observations of galaxy clusters with the X-ray Integral Field Unit onboard the Athena mission

The X-ray Integral Field Unit (X-IFU) is the cryogenic imaging spectrometer onboard the ESA L2 mission Athena. With its array of almost 3840 superconducting Transition Edge Sensors micro-calorimeters, the X-IFU will provide spatially resolved (5" over the field of view) high-resolution spectroscopy (2.5 eV FWHM up to 7 keV) in the 0.2-12 keV energy band. These transformational capabilities will allow the X-IFU to probe the Hot and Energetic Universe, and notably measure the physical properties of large-scale structures with unprecedented accuracy. Starting from numerically-simulated massive (1014 Mo) galaxy clusters at different steps of their evolution, we investigate the capabilities of the X-IFU in recovering chemical abundances, redshift and gas temperature spatial distributions across time, making use of full field-of-view End-To-End simulations of X-IFU observations. This work serve as feasibility study for the Chemical Enrichment of the Universe science objective. We show that using 100 ks observations, the X-IFU will provide an unprecedented spatially-accurate knowledge of the physics of the ICM (abundances, temperature, bulk-motion). We also demonstrate that challenges related to the data analysis of extended sources with very high-resolution spectrometers (e.g. binning, line of sight mixing, particle background) need to be thoroughly addressed to maximise the science of the instrument.